This proposal is titled "Models of Delivery of Prenatal and Childbirth Care." The longterm objective of this research is to obtain knowledge about quality outcomes of childbirth care to inform future health care policies. The specific aims of this research are to investigate and compare two different models of prenatal and birth care delivery in a single community in terms of three dimensions of quality outcomes of care: clinical outcomes, satisfaction and cost. The models of care are a freestanding birth center staffed by certified nurse midwives and a physician practice that utilizes a hospital for low-risk deliveries. This proposal is a prospective research design using a cohort method for subject selection with 536 subjects in each group.